DESCRIPTION (applicant s abstract): This project will study the impact of early-life conditions and prevailing living conditions such as socioeconomic status, nutrition, and the disease environment, on longevity. More specifically, the extent to which changes over the life course and prevailing living conditions interact with, and alter the impact of experiences early in life, will be considered. By using a unique longitudinal database at the individual level, together with appropriate statistical methods, it will be possible to empirically test several hypotheses that have been much debated in demographic and epidemiological research, and to shed new light on long-term processes. The database includes cause-specific mortality and economic information at the individual, family, and community levels.